From The Why-Didn't-Anyone-Think-Of-This-Sooner Department: 30-Use Free Trials Instead Of 30-Days

Most subscription based online services come with some form of
free trial period. The problem is that, as happened with Williams
and Flow, you can forget to try out the product until you're
close to the end of the free period. In this case, everybody
loses: you can't get to use the product properly, and the
business loses on a potential sale.